You can call Koodo and have them deactivate then reactivate the service. Takes maybe 30 seconds. All messages would be lost and the service would need to be set up again with the greeting and password. If you can, call from another line so the agent can stay with you during the voicemail setup.

This would be the easiest/quickest route to get the voicemail working.

1-866-995-6636
Option 5 for customer service
or
Option 6 for technical support